This invention relates to a wide angle lens of a retro-focus type, and more particularly to an objective lens adapted for use in a single lens reflex camera and having a back focus of a length greater than the focal length thereof.
Hitherto, the conventional type wide angle lens of this kind suffers from shortcomings in that the wider the angle of field, the more difficult will be the compensation of the various abberations, such that it is extremely difficult to provide a wide angle lens which has a large relative aperture of high brightness.
It is a principal object of the invention to provide a wide angle lens system of the retro-focus type for use in a photographic camera, said system having a field angle of 64.degree. to 76.degree., a relative aperture of F/2.8 to F/2 and a back focus of a length of 1.06 to 1.32 times as long as the focal length, yet being highly compensated for the various abberations.